The invention relates to a connecting means for the releasable connection of a first component and a second component, in particular, for the releasable connection of furniture or machine parts, comprising
a first connecting element arranged on the first component and
a second connecting element arranged on the second component,
wherein the first connecting element and the second connecting element are releasably connected to one another in the connected state of the components and one of the connecting elements comprises a retaining part which, in a retaining position, interacts with the other one of the connecting elements such that any relative movement of the first connecting element and the second connecting element along a direction of connection is prevented and which, in a release position, allows a relative movement of the first connecting element and the second connecting element along the direction of connection.
Furthermore, the present invention relates to a method for releasing a connection between a first component, on which a first connecting element is arranged, and a second component, on which a second connecting element is arranged, wherein one of the connecting elements comprises a retaining part which, in a retaining position, interacts with the other one of the connecting elements such that any relative movement of the first connecting element and the second connecting element along the direction of connection is prevented, and wherein to release the connection the retaining part is moved from the retaining position into a release position, in which the retaining part allows a relative movement of the first connecting element and the second connecting element along the direction of connection.
Such connecting means and methods are known.
It is known, in particular, to use cabinet catches each comprising an eccentric disk and a stay bolt for the releasable connection of furniture components.
With the known connecting means it is of disadvantage that the retaining part is moved into the release position by means of a tool which engages in the connecting means and so direct access to the connecting means must be provided for the tool.
Particularly in the case of cabinet catches which comprise eccentric disks and stay bolts the components to be connected to one another are weakened by the crossing bores required in these components in such a manner that with the slightest load, in certain circumstances even during normal use of the furniture, the connection will break down due to the connecting elements breaking out of the respectively associated component. Since the eccentric disk absorbs the transferable traction force of the connection due to stress on the wall of the component hole, into which the eccentric disk is inserted, by way of bearing tension, a minimum distance between the eccentric disk and a contact surface, with which the component accommodating the eccentric disk abuts on the additional component, is necessary in order to ensure that the admissible limit shearing strain of the material of this component is not exceeded. On account of this minimum distance the stay bolt which engages in the eccentric disk in the connected state must be of such a length that it is susceptible to breaking out of the component, in which it is accommodated, when any lateral impact occurs. Furthermore, the spatially varying bearing tension at the wall of the hole, in which the eccentric disk is accommodated, leads to tilting of the eccentric disk which may result in the eccentric disk protruding beyond the component, in which it is accommodated.
A further disadvantage of the known connecting means consists in the fact that these always remain at least partially visible even in the connected state of the components on account of the direct access required for the tool, which impairs the optical impression of the piece of furniture produced from these components or the machine produced from these components.
The object underlying the present invention is therefore to provide a connecting means of the type specified at the outset which makes a reliable releasable connection of two components with one another possible without weakening the relevant components unnecessarily due to channels.
This object is accomplished in accordance with the invention, in a connecting means having the features of the preamble to claim 1, in that the retaining part can be moved from the retaining position into the release position by means of a driving magnetic field which acts on the connecting means from outside the connecting means and is variable with time.
The inventive concept offers the advantage that the retaining part can be moved into the release position without a direct mechanical engagement in the connecting means being required. On the contrary, the movement of the retaining part is brought about from outside the connecting means without any direct contact of a corresponding drive device with the connecting means being necessary.
Consequently, it is no longer necessary to provide direct access to the connecting means for a tool through one of the components connected to one another for the mechanical actuation of the retaining part. Since, as a result, additional access passages or access bores can be dispensed with, the components connected to one another are not weakened unnecessarily by additional channels.
Furthermore, no visible connecting elements or cover flaps impair the optical appearance of the product assembled from the components, for example, the finished piece of furniture.
In the field of mechanical engineering, connections may be realized by means of the inventive connecting means, with which an additional channel in the component surfaces has to be avoided for constructional reasons. Furthermore, it is also possible to connect an additional component when it is no longer possible to connect an additional component by means of one of the known connecting means due to components already connected.
As a result of the fact that it is no longer necessary to have crossing bores at the edge of the components to be connected, these components are weakened to a lesser extent. The risk of the connecting elements breaking out of the components is thus reduced.
In order to establish the releasable connection between the two components to be connected to one another, a driving magnetic field is not absolutely necessary. On the contrary, it may be provided for the retaining part to be movable from the release position into the retaining position, for example, by means of elastic forces during the establishment of the connection.
In a preferred development of the inventive connecting means it is, however, provided for the retaining part to be movable from the release position into the retaining position by means of a driving magnetic field. As a result, any unintentional establishment of the connection between the two components can be prevented.
No further details have so far been given concerning the type of time variation of the driving magnetic field.
It is, for example, possible for the retaining part to be movable by means of a rotating driving magnetic field. Such a rotating driving magnetic field can interact directly with a magnetic element comprising a magnet in order to cause this to move.
Alternatively or supplementary hereto, it may also be provided for the retaining part to be movable by means of a driving magnetic field with an amplitude variable with time. In particular, an alternating magnetic field which varies periodically and with time can be used. An induction current, which can be used for bringing about the movement of the retaining part into the release position, can, for example, be generated in the connecting means by means of such a driving magnetic field.
In principle, it is possible for the retaining part to be movable directly as a result of interaction of the retaining part with the driving magnetic field.
In preferred developments of the invention, it is, however, provided for the connecting means to comprise a coupling means, as a result of the interaction of which with the driving magnetic field the retaining part is movable indirectly.
Such a coupling means may, for example, comprise a unit for generating an induction current as a result of interaction with the driving magnetic field.
This induction current may be used, for example, to operate a heating element which can be fed with the induction current.
In this case, it may be provided, in particular, for the retaining part to comprise an element deformable due to temperature variation, preferably a bimetallic strip. In this case, the retaining part can be moved from the retaining position into the release position due to deformation of the element deformable due to temperature variation when the heating element is fed with the induction current generated as a result of interaction with the driving magnetic field.
Alternatively or supplementary to driving the retaining part as a result of induction, it may also be provided for the coupling means to comprise a magnetic element which can be driven by means of the driving magnetic field to perform a movement within the connecting means. The movement of the magnetic element is thereby brought about by a direct magnetic interaction of the magnetic element with the driving magnetic field.
The movement of the retaining part can, in this case, be brought about directly as a result of interaction of the retaining part with the magnetic element.
It may, in particular, be provided for the magnetic element to have an entraining element which interacts with a suitable entraining element of the retaining part such that the movement of the magnetic element brought about by the driving magnetic field can be transferred to the retaining part.
In a preferred development of the invention it is provided for the magnetic element to be drivable by means of the driving magnetic field to perform a rotary movement. This rotary movement can then be transferred to the retaining part so that the retaining part can be turned into the retaining position.
It is particularly favorable when the magnetic element can be driven to perform an oscillating rotary movement. In this case, the magnetic element can be moved away from the retaining part when the retaining part is jammed in a blocked position in order to subsequently be accelerated by the driving magnetic field over a large rotary angle and to be able to transfer a correspondingly large momentum to the retaining part so that the retaining part is released from the blocked position. As a result of this effect similar to a sledge hammer or drive screw a considerable torque can be transferred to the retaining part so that a retaining part securely turned into the other connecting means can also be released from the retaining position in this manner.
It is particularly favorable when the rotary angle which can be covered by the magnetic element during the oscillating rotary movement is more than approximately 90xc2x0, preferably more than approximately 150xc2x0. The larger the rotary angle which the magnetic element can cover during the rotary movement, the longer the path of acceleration for the magnetic element and the greater the momentum which can be transferred from the magnetic element to the retaining element.
In a preferred development of the invention a magnetic element is used which comprises a permanent magnet magnetized transversely to the longitudinal axis of the magnetic element. Such a magnetic element may be driven in a simple manner to perform a rotary movement about its longitudinal axis as a result of interaction with a rotating driving magnetic field and this movement requires less space in the connecting means than would be the case for a rotation of the magnetic element about a transverse axis thereof.
Instead of a direct interaction of the magnetic element with the retaining part, it may also be provided for the coupling means to comprise an unlocking element which can be moved into an unlocking position as a result of interaction with the magnetic element, wherein the retaining part is located in the release position when the unlocking element is in the unlocking position.
Instead of a rotary movement, the magnetic element can also be drivable to perform a linear movement by means of the driving magnetic field.
It is particularly favorable when the magnetic element can be driven to perform a linear reciprocating movement. When the retaining part and/or an unlocking element which is present where applicable are located in a blocked position, the magnetic element can, in this case, be released from the retaining part and the unlocking element, respectively, in order to again be accelerated by the driving magnetic field and to achieve an adequately large momentum which is sufficient to release the retaining part and/or the unlocking element from the blocked position.
In order to bring about a linear movement of the magnetic element it is of advantage when the magnetic element comprises a permanent magnet magnetized essentially parallel to the longitudinal axis of the magnetic element.
Furthermore, it is of advantage when the coupling means comprises an elastic element for reversing the direction of movement of the magnetic element. Such an elastic element can store the kinetic energy of the magnetic element as elastic energy during the reversal procedure and transfer this energy again to the magnetic element after a completed reversal of the direction of movement in order to accelerate this magnetic element, in addition.
In a preferred development of the inventive connecting means it is provided for the retaining part to comprise a shaft with a thread, preferably an external thread. If the retaining part is screwed by means of a thread into a corresponding counterthread of the other connecting element, large traction forces can be absorbed by the connecting means which allows the surfaces, on which the components to be connected to one another abut on one another, to be securely tightened against one another so that no gap remains between the components.
In the case of the known connecting means, in particular, in the case of a connecting means comprising an eccentric disk and a stay bolt this is mostly not possible because the area of the edge of the component including the eccentric disk, which is weakened due to the crossing bores, is not in a position to activate the necessary reaction tensions without thereby being deformed to a considerable degree. This results in the weakened edge area breaking down before the contact surfaces of the components to be connected to one another touch.
Alternatively or supplementary to a thread, the retaining part may be provided with a locking tongue which is locked to the other connecting element in the retaining position of the retaining part.
In order to be able to bring the components to be connected to one another into engagement with one another before the retaining part is moved into the retaining position, the retaining part is preferably mounted in one of the connecting elements for displacement along the direction of connection.
It is particularly favorable when the retaining part is spring mounted in one of the connecting elements. As a result, any damage to the retaining part while the two components are being brought together prior to establishing the connection can be avoided at the same time and the retaining part can be pretensioned against the other connecting element which facilitates the movement of the retaining part into the retaining position.
In order to avoid the connecting means becoming visible after establishment of the connection between the components and to prevent an unsightly gap resulting between the components in the connected position, it is of advantage when the connecting elements can be secured in the first component and in the second component, respectively, such that outer surfaces of these components abut on one another in the connected position.
It may, in particular, be provided for one of the connecting elements or both connecting elements to be anchored in the associated component by means of a respective outer thread. In this case, a transfer of force between the respective connecting element and the associated component extending over many thread flanks is provided for in the assembled state, in which the connecting elements are secured in the associated component, and so the occurrence of local peak tensions, which exceed the admissible material parameters of the respective component, is avoided.
A visibility of the connecting means in the connected state of the components may be avoided, in particular, due to the fact that one of the connecting elements has a receiving means, into which the other connecting element dips at least partially in the connected position.
If it is advantageously provided for the other connecting element to abut areally on an inner wall of the receiving means in the connected position, wherein the normal to surface of the inner wall is aligned transversely to the direction of connection, the connection established between the components by means of the inventive connecting means can absorb considerable shearing forces.
Known connecting means, in particular, connecting means comprising an eccentric disk and a stay bolt are not in a position to do this because the required, crossing bores weaken at least one of the components too greatly and so additional dowels are necessary for the transfer of shearing forces and this entails additional resources of time and costs for the production of the connection.
In preferred developments of the invention it is provided for at least one of the connecting elements to comprise an anchoring part which is anchored in the associated component in the assembled state and a connecting part which projects beyond an outer surface of the associated component and for the connecting part to have a smaller extension in the direction of connection than the anchoring part. As a result of this design, the connecting element anchored in the associated component becomes unsusceptible with respect to lateral impact. Such lateral impact occurs frequently, for example, during the assembly of a piece of furniture when a furniture component with stay bolts screwed into it falls over due to carelessness and thereby falls onto one of these stay bolts. With the known connecting means which, as already explained above, comprise stay bolts projecting of necessity to a considerable extent beyond the outer surface of the associated component such an impact often leads to the stay bolts breaking out of the associated component.
No further details have so far been given concerning the type of generation of the driving magnetic field.
In one embodiment, a drive device is provided for releasing a connection between the first component and the second component established by means of an inventive connecting means, this device comprising a means for generating the driving magnetic field variable with time, by means of which the retaining part can be moved from the retaining position into the release position.
Such a drive device is preferably designed so as to be transportable in order to be brought in a simple manner to the respective assembly location of the two components and to be positioned relative to the connecting means in a suitable manner.
The handling capability of the drive device is facilitated when this is advantageously provided with a handle.
In order to be able to drive a magnetic element provided in the connecting means to perform a movement in the connecting means, the drive device advantageously comprises a means for generating a rotating driving magnetic field.
In order to be able to use the drive device not only for establishing but also for releasing the connection between the components, the direction of rotation of the driving magnetic field is preferably reversible.
It is possible to generate a rotating driving magnetic field in a particularly simple manner when the drive device comprises a rotatable driving magnet and a motor for bringing about a rotary movement of the driving magnet.
In order to keep the space required in the drive device for the rotary movement of the driving magnet as small as possible, it is preferably provided for the driving magnet to be essentially cylindrical and magnetized transversely to its longitudinal axis.
Alternatively or supplementary to a rotatable driving magnet it may also be provided for the drive device to have a coil arrangement which comprises several coils which are preferably aligned antiparallel to one another and can be supplied by means of a suitable control circuit with coil currents variable with time such that the driving magnetic field resulting due to superposition of the individual coil magnetic fields is variable with time in the desired manner, in particular, essentially carries out a linear or a rotary movement.
In a preferred development of the inventive drive device it is provided for a periodically variable driving magnetic field to be generated by the means for generating the driving magnetic field, the frequency of this magnetic field corresponding essentially to a resonance frequency of a coupling means of the connecting means, as a result of the interaction of which with the driving magnetic field the retaining part can be moved. The resonance frequency of the coupling means is thereby to be understood as that frequency of an oscillating movement of the coupling means driven by means of the driving magnetic field, with which the momentum transferred from the driving magnetic field to the coupling means is at a maximum.
As a result, it is possible to release the retaining part in a particularly efficient manner from blocked positions, in which the retaining part is stuck, on its way from the retaining position into the release position.
In order to avoid the retaining part being brought during the establishment of the connection between the components into a retaining position, in which it is so rigidly anchored that it can no longer be released from the retaining position by means of the drive device, the drive device can preferably be switched into an operating state, in which the frequency of the driving magnetic field is shifted in relation to the resonance frequency of the coupling means, preferably by at the most approximately 10%. This operating state of the drive device can be used to bring the retaining part from the release position into the retaining position. Since, in this operating state, the momentum transferred to the coupling means and thus to the retaining part is smaller than the maximum transferable momentum, it is ensured that a connection established by means of the drive device can be released again with certainty by the same drive device.
In another embodiment, an assembly set is provided for establishing a releasable connection between a first component and a second component which comprises an inventive connecting means and an inventive drive device.
A further object underlying the present invention is to provide a method for releasing a connection between two components of the type described at the outset, by means of which the components can be released from one another without the relevant components needing to be weakened unnecessarily by channels.
This object is accomplished in accordance with an illustrated embodiment of the invention, in a method wherein the retaining part is moved from the retaining position into the release position by means of a driving magnetic field variable with time and acting on the connecting means from outside the connecting means.
The inventive method offers the advantage that no additional channels need be provided in the relevant components in order to facilitate a direct mechanical engagement of a tool in the connecting means for releasing the connection between the components. In addition, it is possible to arrange the connecting means invisibly on the components connected to one another in the connected state.